A casino is a gambling establishment where patrons can gamble for money. The concept of casinos grew in popularity during the last half of the 20th century as more countries changed their laws to allow them. Today, there are more than 1,000 casinos in the world. The United States has the largest number, with Las Vegas being the most famous.
Gambling almost certainly predates recorded history, with primitive protodice and carved six-sided dice among the earliest archaeological finds. However, the modern casino as a place for people to find multiple ways to gamble under one roof did not develop until the 16th century, when European gambling crazes led to private parties called ridotti being held by Italian aristocrats at their homes (source: Schwartz).
Casinos earn most of their income from slot machines, which require only a small amount of money and do not depend on player skill. The machines display bands of colored shapes rolling on reels (physical or video) and pay out according to a predetermined formula.
Table games are the secondary source of casino revenue. Baccarat, chemin de fer and blackjack are prominent in Europe; American casinos offer roulette, craps and trente et quarante.
A comp is a free good or service given to a casino player based on how much he or she spends there. Casinos usually offer them based on how long players stay and the size of their bets, with big spenders getting free hotel rooms, meals or tickets to shows. Many casinos also have club cards similar to airline frequent flyer programs that give patrons points they can exchange for coupons for free slot play.